After losing 150 pounds since undergoing a sleeve gastrectomy, MasterChef judge Graham Elliot is on to his next challenge. He completed his first 10K in Chicago on Memorial Day and has begun training for the Chicago Marathon, which will take place on October 12th. (Fellow judge Joe Bastianich has run several marathons.)

“I’m very excited but also nervous,” Elliot, 37, tells PEOPLE. “But I’m telling you even if it takes 12 hours and I have to crawl on my knees and hands to get over the finish line, I will make it happen.”

So far, the chef of GE Bistro in Chicago and Primary in Greenwich, Connecticut, can run an 11-minute mile. He finished the 10K in about 1 hour and 16 minutes. “The big thing for me is being able to run and talk at the same time,” he says. “My trainer said focusing on a steady pace and being able to hold a conversation is a big thing. It’s a good way to be more in the moment.”

The award-winning chef will be running the marathon on behalf of Smile Train, a charity that provides free cleft repair surgery for people in need. “I’m publicly saying I’m doing the marathon so excuses are not an option. This is a real commitment.”

His dedication to healthier eating changed his mind set during the latest round of judging food on the set of MasterChef this season. “I definitely have smaller bites than before. And I was nervous about getting too full. There would be 15 lobster dishes to taste! I’m happy to say there were no incidents.”

Another change? “I’m finding that I eat and get hungrier sooner than I expected,” he explains. “I don’t know if its just because the real estate in smaller in my stomach but I’ll eat two scallops and feel full, then an hour and a half later, I need to eat a small salad.”

That’s just great. To Graham’s health and to success in keeping it off.

gh on May 27th, 2014

Yo, why don’t you gtfo. No need to rain on someone’s parade for doing something positive for themselves.

Sandy Lefebvre on May 27th, 2014

Graham looks AH-mazing! I was thrilled to see him looking so slim and trim on the show last night! He has to feel like a million bucks so, congrats to him!

yahoo on May 27th, 2014

OMG he looks like a totally, different youthful man. I’m overjoyed for his success.

JM on May 27th, 2014

That was a nasty comment about his weight. You have no idea about his health in the first place. Maybe obesity runs in his family, he had an underlying health condition who knows. Don’t judge. He looks fantastic and should be so proud. Way to go Graham.

George Clooney's Latest Beard on May 27th, 2014

Good for him. Glad to see he is taking control of his health…keep up the great work!!

Jr on May 27th, 2014

Now, if he would just lose those white glasses.

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